Avoid SharePath call when launching app with shared path

If a path is already shared, we can avoid the extra seneschal dbus call.

This code was originally written before GuestOsSharePath::IsPathShared()
was available.

Change-Id: Ia92dcad3e3202f40606a0e8b7620e0ea76847c58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2596472
Auto-Submit: Joel Hockey <joelhockey@chromium.org>
Commit-Queue: Nicholas Verne <nverne@chromium.org>
Commit-Queue: Jason Lin <lxj@google.com>
Reviewed-by: Nicholas Verne <nverne@chromium.org>
Reviewed-by: Jason Lin <lxj@google.com>
Cr-Commit-Position: refs/heads/master@{#838587}

chrome/browser/chromeos/crostini/crostini_util.cc

@@ -177,6 +177,9 @@ void LaunchApplication(
 
   crostini_tracker->OnAppLaunchRequested(app_id, display_id);
 
+  auto* share_path = guest_os::GuestOsSharePath::GetForProfile(profile);
+  const auto vm_name = registration.VmName();
+
   // Share any paths not in crostini.  The user will see the spinner while this
   // is happening.
   std::vector<base::FilePath> paths_to_share;
@@ -196,7 +199,8 @@ void LaunchApplication(
           "Cannot share file with crostini: " + url.DebugString());
     }
     if (url.mount_filesystem_id() !=
-        file_manager::util::GetCrostiniMountPointName(profile)) {
+            file_manager::util::GetCrostiniMountPointName(profile) &&
+        !share_path->IsPathShared(vm_name, url.path())) {
       paths_to_share.push_back(url.path());
     }
     launch_args.push_back(path.value());
@@ -207,8 +211,7 @@ void LaunchApplication(
                                     display_id, std::move(launch_args),
                                     std::move(callback), true, "");
   } else {
-    const auto vm_name = registration.VmName();
-    guest_os::GuestOsSharePath::GetForProfile(profile)->SharePaths(
+    share_path->SharePaths(
         vm_name, std::move(paths_to_share), /*persist=*/false,
         base::BindOnce(OnSharePathForLaunchApplication, profile, app_id,
                        std::move(registration), display_id,